1. Field of the Invention
The present invention relates to a backlight source device suitable for a LCD, a display screen, a backlight plate, a broadcast plate, and other equipment having a backlight source device.
2. Description of the Prior Art
The light guiding plate 1 of a prior art backlight source device is disclosed in FIGS. 1 and 2. The pattern for guiding lateral light source 11 is a plurality of trenches arranged in parallel formed by printing, or diffusing units formed by convex strips, or point matrix, or a plurality of trenches arranged in parallel with equal space and equal depth for diffusing and reflecting a lateral light source 11. The areas of all parts of the light guiding surface 12 thereof are identical, and therefore, each part has identical illumination.
However, the light from the front surface of the light guiding plate 1 of the prior art backlight source device is not often used. Since the areas of all parts of the light guiding surface are identical, and therefore, each part has identical illumination. In general, the central portion of the lateral light source 11 has illumination stronger than that of the two sides thereof. Thus, the prior art light diffusng trenches with equal depths, height and arranged in parallel will induce a non-uniform light distribution of the prior art light guiding plate 1. Namely, the portion near the central portion of the lateral light source 11 has stronger illumination, while the two sides of the lateral light source have weaker illumination. Thus, "light regions" and "dark regions" are formed. This is not an ideal circumstance.